Merge branch '2'

.travis.yml

@@ -4,6 +4,8 @@ sudo: false
 
 language: php
 
+dist: precise
+
 php:
   - 5.6
   - 7.0

README.md

@@ -20,6 +20,7 @@ This module provides a number of useful grid field components:
   custom grid field detail views including tabs, breadcrumbs and other CMS
   features.
 * `GridFieldTitleHeader` - a simple header which displays column titles.
+* `GridFieldConfigurablePaginator` - a paginator for GridField that allows customisable page sizes.
 
 This branch will aim for compatibility with SilverStripe 4.x. 
 

composer.json

@@ -21,6 +21,9 @@
     "require": {
         "silverstripe/framework": "~4.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^5.7"
+    },
     "extra": {
         "installer-name": "gridfieldextensions",
         "branch-alias": {

css/GridFieldExtensions.css

@@ -73,8 +73,7 @@
  */
 
 .ss-gridfield-add-new-multi-class {
-  margin-bottom: 8px !important;
+  margin-bottom: 8px !important;white-space: nowrap;
-  white-space: nowrap;
 }
 
 .ss-gridfield-add-new-multi-class .field {
@@ -166,12 +165,13 @@
 }
 
 .ss-gridfield-orderable .col-reorder .handle {
-  cursor: move;
+
-  padding: 16px 0 11px;
+  cursor: move;padding: 16px 0 11px;
 }
 
 .ss-gridfield-orderable .col-reorder .handle .icon {
-  line-height: 100%;
+  line-
+  height: 100%;
   font-size: 1.5em;
 }
 
@@ -199,3 +199,25 @@
   background-position: -40px 9px !important;
   margin-right: 0;
 }
+
+/**
+ * GridFieldConfigurablePaginator
+ */
+.ss-gridfield-configurable-paginator .pagination-page-size {
+  color: #fff;
+  float: left;
+  padding: 6px 0;
+}
+
+.ss-gridfield-configurable-paginator .pagination-page-size-select {
+  margin-left: 0;
+  width: auto;
+}
+
+.ss-gridfield-configurable-paginator .ss-gridfield-pagesize-submit {
+  display: none;
+}
+
+.ss-gridfield-configurable-paginator .pagination-page-number input {
+  text-align: center;
+}

docs/en/index.md

@@ -106,3 +106,36 @@ class Item extends DataObject {
 
 **Please NOTE:** There is a limitation when using `GridFieldOrderableRows` on unsaved data objects; namely, that it doesn't work as without data being saved, the list of related objects has no context. Please check `$this->ID` before adding the `GridFieldOrderableRows` component to the grid field config (or even, before adding the gridfield at all). 
 
+Configurable Paginator
+----------------------
+
+The `GridFieldConfigurablePaginator` component allows you to have a page size dropdown added to your GridField
+pagination controls. The page sizes are configurable via the configuration system, or at call time using the public API.
+To use this component you should remove the original paginator component first:
+
+```php
+$gridField->getConfig()
+    ->removeComponentsByType('GridFieldPaginator')
+    ->addComponent(new GridFieldConfigurablePaginator());
+```
+
+You can configure the page sizes with the configuration system. Note that merging is the default strategy, so to replace
+the default sizes with your own you will need to unset the original first, for example:
+
+```php
+# File: mysite/_config.php
+Config::inst()->remove('GridFieldConfigurablePaginator', 'default_page_sizes');
+Config::inst()->update('GridFieldConfigurablePaginator', 'default_page_sizes', array(100, 200, 500));
+```
+
+You can also override these at call time:
+
+```php
+$paginator = new GridFieldConfigurablePaginator(100, array(100, 200, 500));
+
+$paginator->setPageSizes(array(200, 500, 1000));
+$paginator->setItemsPerPage(500);
+```
+
+The first shown record will be maintained across page size changes, and the number of pages and current page will be
+recalculated on each request, based on the current first shown record and page size.

javascript/GridFieldExtensions.js

@@ -387,5 +387,14 @@
 				if(this.hasClass("ui-droppable")) this.droppable("destroy");
 			}
 		});
+
+        /**
+         * GridFieldConfigurablePaginator
+         */
+        $('.ss-gridfield-configurable-paginator .pagination-page-size-select').entwine({
+            onchange: function () {
+                this.parent().find('.ss-gridfield-pagesize-submit').trigger('click');
+            }
+        });
 	});
 })(jQuery);

src/GridFieldAddNewInlineButton.php

@@ -181,7 +181,6 @@ class GridFieldAddNewInlineButton implements GridField_HTMLProvider, GridField_S
         $editable = $grid->getConfig()->getComponentByType(GridFieldEditableColumns::class);
         /** @var GridFieldOrderableRows $sortable */
         $sortable = $grid->getConfig()->getComponentByType(GridFieldOrderableRows::class);
-        $form     = $editable->getForm($grid, $record);
 
         if (!singleton($class)->canCreate()) {
             return;
@@ -192,6 +191,7 @@ class GridFieldAddNewInlineButton implements GridField_HTMLProvider, GridField_S
             $item  = $class::create();
             $extra = array();
 
+            $form = $editable->getForm($grid, $record);
             $form->loadDataFrom($fields, Form::MERGE_CLEAR_MISSING);
             $form->saveInto($item);
 

src/GridFieldConfigurablePaginator.php

@@ -0,0 +1,453 @@
+<?php
+
+namespace Symbiote\GridFieldExtensions;
+
+use Exception;
+use SilverStripe\Core\Config\Configurable;
+use SilverStripe\Forms\GridField\GridField;
+use SilverStripe\Forms\GridField\GridFieldPaginator;
+use SilverStripe\Forms\GridField\GridField_FormAction;
+use SilverStripe\Forms\GridField\GridState_Data;
+use SilverStripe\ORM\ArrayList;
+use SilverStripe\ORM\Limitable;
+use SilverStripe\ORM\SS_List;
+use SilverStripe\ORM\UnsavedRelationList;
+use SilverStripe\View\ArrayData;
+
+/**
+ * GridFieldConfigurablePaginator paginates the {@link GridField} list and adds controls to the bottom of
+ * the {@link GridField}. The page sizes are configurable.
+ */
+class GridFieldConfigurablePaginator extends GridFieldPaginator
+{
+    use Configurable;
+
+    /**
+     * Specifies default page sizes
+     *
+     * @config
+     * @var int
+     */
+    private static $default_page_sizes = array(15, 30, 60);
+
+    /**
+     * @var GridField
+     */
+    protected $gridField;
+
+    /**
+     * @var GridState_Data
+     */
+    protected $gridFieldState;
+
+    /**
+     * @var int[]
+     */
+    protected $pageSizes = array();
+
+    /**
+     * @param int $itemsPerPage  How many items should be displayed per page
+     * @param int $pageSizes The page sizes to show in the dropdown
+     */
+    public function __construct($itemsPerPage = null, $pageSizes = null)
+    {
+        $this->setPageSizes($pageSizes ?: $this->config()->get('default_page_sizes'));
+
+        if (!$itemsPerPage) {
+            $itemsPerPage = $this->pageSizes[0];
+        }
+
+        parent::__construct($itemsPerPage);
+    }
+
+    /**
+     * Get the total number of records in the list
+     *
+     * @return int
+     */
+    public function getTotalRecords()
+    {
+        return (int) $this->getGridField()->getList()->count();
+    }
+
+    /**
+     * Get the first shown record number
+     *
+     * @return int
+     */
+    public function getFirstShown()
+    {
+        $firstShown = $this->getGridPagerState()->firstShown ?: 1;
+        // Prevent visiting a page with an offset higher than the total number of items
+        if ($firstShown > $this->getTotalRecords()) {
+            $this->getGridPagerState()->firstShown = $firstShown = 1;
+        }
+        return $firstShown;
+    }
+
+    /**
+     * Set the first shown record number. Will be stored in the state.
+     *
+     * @param  int $firstShown
+     * @return $this
+     */
+    public function setFirstShown($firstShown = 1)
+    {
+        $this->getGridPagerState()->firstShown = (int) $firstShown;
+        return $this;
+    }
+
+    /**
+     * Get the last shown record number
+     *
+     * @return int
+     */
+    public function getLastShown()
+    {
+        return min($this->getTotalRecords(), $this->getFirstShown() + $this->getItemsPerPage() - 1);
+    }
+
+    /**
+     * Get the total number of pages, given the current number of items per page. The total
+     * pages might be higher than <totalitems> / <itemsperpage> if the first shown record
+     * is half way through a standard page break point.
+     *
+     * @return int
+     */
+    public function getTotalPages()
+    {
+        // Pages before
+        $pages = ceil(($this->getFirstShown() - 1) / $this->getItemsPerPage());
+
+        // Current page
+        $pages++;
+
+        // Pages after
+        $pages += ceil(($this->getTotalRecords() - $this->getLastShown()) / $this->getItemsPerPage());
+
+        return (int) $pages;
+    }
+
+
+    /**
+     * Get the page currently active. This is calculated by adding one to the previous number
+     * of pages calculated via the "first shown record" position.
+     *
+     * @return int
+     */
+    public function getCurrentPage()
+    {
+        return (int) ceil(($this->getFirstShown() - 1) / $this->getItemsPerPage()) + 1;
+    }
+
+    /**
+     * Get the next page number
+     *
+     * @return int
+     */
+    public function getNextPage()
+    {
+        return min($this->getTotalPages(), $this->getCurrentPage() + 1);
+    }
+
+    /**
+     * Get the previous page number
+     *
+     * @return int
+     */
+    public function getPreviousPage()
+    {
+        return max(1, $this->getCurrentPage() - 1);
+    }
+
+    /**
+     * Set the page sizes to use in the "Show x" dropdown
+     *
+     * @param array $pageSizes
+     * @return $this
+     */
+    public function setPageSizes(array $pageSizes)
+    {
+        $this->pageSizes = $pageSizes;
+
+        // Reset items per page
+        $this->setItemsPerPage(current($pageSizes));
+
+        return $this;
+    }
+
+    /**
+     * Get the sizes for the "Show x" dropdown
+     *
+     * @return array
+     */
+    public function getPageSizes()
+    {
+        return $this->pageSizes;
+    }
+
+    /**
+     * Gets a list of page sizes for use in templates as a dropdown
+     *
+     * @return ArrayList
+     */
+    public function getPageSizesAsList()
+    {
+        $pageSizes = ArrayList::create();
+        $perPage = $this->getItemsPerPage();
+        foreach ($this->getPageSizes() as $pageSize) {
+            $pageSizes->push(array(
+                'Size' => $pageSize,
+                'Selected' => $pageSize == $perPage
+            ));
+        }
+        return $pageSizes;
+    }
+
+    /**
+     * Get the GridField used in this request
+     *
+     * @return GridField
+     * @throws Exception If the GridField has not been previously set
+     */
+    public function getGridField()
+    {
+        if ($this->gridField) {
+            return $this->gridField;
+        }
+        throw new Exception('No GridField available yet for this request!');
+    }
+
+    /**
+     * Set the GridField so it can be used in other parts of the component during this request
+     *
+     * @param GridField $gridField
+     * @return $this
+     */
+    public function setGridField(GridField $gridField)
+    {
+        $this->gridField = $gridField;
+        return $this;
+    }
+
+    public function handleAction(GridField $gridField, $actionName, $arguments, $data)
+    {
+        $this->setGridField($gridField);
+
+        if ($actionName !== 'paginate') {
+            return;
+        }
+        $state = $this->getGridPagerState();
+
+        $state->firstShown = (int) $arguments['first-shown'];
+        $state->pageSize = $data[$gridField->getName()]['page-sizes'];
+
+        $this->setItemsPerPage($state->pageSize);
+    }
+
+    public function getManipulatedData(GridField $gridField, SS_List $dataList)
+    {
+        // Assign the GridField to the class so it can be used later in the request
+        $this->setGridField($gridField);
+
+        // Retain page sizes during actions provided by other components
+        $state = $this->getGridPagerState();
+        if (is_numeric($state->pageSize)) {
+            $this->setItemsPerPage($state->pageSize);
+        }
+
+        if (!($dataList instanceof Limitable) || ($dataList instanceof UnsavedRelationList)) {
+            return $dataList;
+        }
+
+        return $dataList->limit($this->getItemsPerPage(), $this->getFirstShown() - 1);
+    }
+
+    /**
+     * Add the configurable page size options to the template data
+     *
+     * {@inheritDoc}
+     *
+     * @param  GridField $gridField
+     * @return ArrayList|null
+     */
+    public function getTemplateParameters(GridField $gridField)
+    {
+        $state = $this->getGridPagerState();
+        if (is_numeric($state->pageSize)) {
+            $this->setItemsPerPage($state->pageSize);
+        }
+        $arguments = $this->getPagerArguments();
+
+        // Figure out which page and record range we're on
+        if (!$arguments['total-rows']) {
+            return;
+        }
+
+        // Define a list of the FormActions that should be generated for pager controls (see getPagerActions())
+        $controls = array(
+            'first' => array(
+                'title' => 'First',
+                'args' => array('first-shown' => 1),
+                'extra-class' => 'btn btn-secondary btn--hide-text btn-sm font-icon-angle-double-left ss-gridfield-firstpage',
+                'disable-previous' => ($this->getCurrentPage() == 1)
+            ),
+            'prev' => array(
+                'title' => 'Previous',
+                'args' => array('first-shown' => $arguments['first-shown'] - $this->getItemsPerPage()),
+                'extra-class' => 'btn btn-secondary btn--hide-text btn-sm font-icon-angle-left ss-gridfield-previouspage',
+                'disable-previous' => ($this->getCurrentPage() == 1)
+            ),
+            'next' => array(
+                'title' => 'Next',
+                'args' => array('first-shown' => $arguments['first-shown'] + $this->getItemsPerPage()),
+                'extra-class' => 'btn btn-secondary btn--hide-text btn-sm font-icon-angle-right ss-gridfield-nextpage',
+                'disable-next' => ($this->getCurrentPage() == $arguments['total-pages'])
+            ),
+            'last' => array(
+                'title' => 'Last',
+                'args' => array('first-shown' => ($this->getTotalPages() - 1) * $this->getItemsPerPage() + 1),
+                'extra-class' => 'btn btn-secondary btn--hide-text btn-sm font-icon-angle-double-right ss-gridfield-lastpage',
+                'disable-next' => ($this->getCurrentPage() == $arguments['total-pages'])
+            ),
+            'pagesize' => array(
+                'title' => 'Page Size',
+                'args' => array('first-shown' => $arguments['first-shown']),
+                'extra-class' => 'ss-gridfield-pagesize-submit'
+            ),
+        );
+
+        if ($controls['prev']['args']['first-shown'] < 1) {
+            $controls['prev']['args']['first-shown'] = 1;
+        }
+
+        $actions = $this->getPagerActions($controls, $gridField);
+
+        // Render in template
+        return ArrayData::create(array(
+            'OnlyOnePage' => ($arguments['total-pages'] == 1),
+            'FirstPage' => $actions['first'],
+            'PreviousPage' => $actions['prev'],
+            'NextPage' => $actions['next'],
+            'LastPage' => $actions['last'],
+            'PageSizesSubmit' => $actions['pagesize'],
+            'CurrentPageNum' => $this->getCurrentPage(),
+            'NumPages' => $arguments['total-pages'],
+            'FirstShownRecord' => $arguments['first-shown'],
+            'LastShownRecord' => $arguments['last-shown'],
+            'NumRecords' => $arguments['total-rows'],
+            'PageSizes' => $this->getPageSizesAsList(),
+            'PageSizesName' => $gridField->getName() . '[page-sizes]',
+        ));
+    }
+
+    public function getHTMLFragments($gridField)
+    {
+        GridFieldExtensions::include_requirements();
+
+        $gridField->addExtraClass('ss-gridfield-configurable-paginator');
+
+        $forTemplate = $this->getTemplateParameters($gridField);
+        if ($forTemplate) {
+            return array(
+                'footer' => $forTemplate->renderWith(
+                    __CLASS__,
+                    array('Colspan' => count($gridField->getColumns()))
+                )
+            );
+        }
+    }
+
+    /**
+     * Returns an array containing the arguments for the pagination: total rows, pages, first record etc
+     *
+     * @return array
+     */
+    protected function getPagerArguments()
+    {
+        return array(
+            'total-rows' => $this->getTotalRecords(),
+            'total-pages' => $this->getTotalPages(),
+            'items-per-page' => $this->getItemsPerPage(),
+            'first-shown' => $this->getFirstShown(),
+            'last-shown' => $this->getLastShown(),
+        );
+    }
+
+    /**
+     * Returns FormActions for each of the pagination actions, in an array
+     *
+     * @param  array     $controls
+     * @param  GridField $gridField
+     * @return GridField_FormAction[]
+     */
+    public function getPagerActions(array $controls, GridField $gridField)
+    {
+        $actions = array();
+
+        foreach ($controls as $key => $arguments) {
+            $action = GridField_FormAction::create(
+                $gridField,
+                'pagination_' . $key,
+                $arguments['title'],
+                'paginate',
+                $arguments['args']
+            );
+
+            if (isset($arguments['extra-class'])) {
+                $action->addExtraClass($arguments['extra-class']);
+            }
+
+            if (isset($arguments['disable-previous']) && $arguments['disable-previous']) {
+                $action = $action->performDisabledTransformation();
+            } elseif (isset($arguments['disable-next']) && $arguments['disable-next']) {
+                $action = $action->performDisabledTransformation();
+            }
+
+            $actions[$key] = $action;
+        }
+
+        return $actions;
+    }
+
+    public function getActions($gridField)
+    {
+        return array('paginate');
+    }
+
+    /**
+     * Gets the state from the current request's GridField and sets some default values on it
+     *
+     * @param  GridField $gridField Not used, but present for parent method compatibility
+     * @return GridState_Data
+     */
+    protected function getGridPagerState(GridField $gridField = null)
+    {
+        if (!$this->gridFieldState) {
+            $state = $this->getGridField()->State->GridFieldConfigurablePaginator;
+
+            // SS 3.1 compatibility (missing __call)
+            if (is_object($state->firstShown)) {
+                $state->firstShown = 1;
+            }
+            if (is_object($state->pageSize)) {
+                $state->pageSize = $this->getItemsPerPage();
+            }
+
+            // Handle free input in the page number field
+            $parentState = $this->getGridField()->State->GridFieldPaginator;
+            if (is_object($parentState->currentPage)) {
+                $parentState->currentPage = 0;
+            }
+
+            if ($parentState->currentPage >= 1) {
+                $state->firstShown = ($parentState->currentPage - 1) * $this->getItemsPerPage() + 1;
+                $parentState->currentPage = null;
+            }
+
+            $this->gridFieldState = $state;
+        }
+
+        return $this->gridFieldState;
+    }
+}

src/GridFieldEditableColumns.php

@@ -124,8 +124,6 @@ class GridFieldEditableColumns extends GridFieldDataColumns implements
         /** @var GridFieldOrderableRows $sortable */
         $sortable = $grid->getConfig()->getComponentByType(GridFieldOrderableRows::class);
 
-        $form = $this->getForm($grid, $record);
-
         foreach ($value[self::POST_KEY] as $id => $fields) {
             if (!is_numeric($id) || !is_array($fields)) {
                 continue;
@@ -139,6 +137,7 @@ class GridFieldEditableColumns extends GridFieldDataColumns implements
 
             $extra = array();
 
+            $form = $this->getForm($grid, $record);
             $form->loadDataFrom($fields, Form::MERGE_CLEAR_MISSING);
             $form->saveInto($item);
 

templates/Symbiote/GridFieldExtensions/GridFieldConfigurablePaginator.ss

@@ -0,0 +1,30 @@
+<tr>
+    <td class="bottom-all" colspan="$Colspan">
+        <span class="pagination-page-size">
+            <%t GridFieldConfigurablePaginator.SHOW 'Show' %>
+            <select name="$PageSizesName" class="pagination-page-size-select" data-skip-autofocus="true">
+            <% loop $PageSizes %>
+                <option <% if $Selected %>selected="selected"<% end_if %>>$Size</option>
+            <% end_loop %>
+            </select>
+            $PageSizesSubmit
+        </span>
+        <% if not $OnlyOnePage %>
+            <div class="datagrid-pagination">
+                $FirstPage $PreviousPage
+                <span class="pagination-page-number">
+                    <%t Pagination.Page 'Page' %>
+                    <input class="text" value="$CurrentPageNum" data-skip-autofocus="true" />
+                    <%t TableListField_PageControls_ss.OF 'of' is 'Example: View 1 of 2' %>
+                    $NumPages
+                </span>
+                $NextPage $LastPage
+            </div>
+        <% end_if %>
+        <span class="pagination-records-number">
+            {$FirstShownRecord}&ndash;{$LastShownRecord}
+            <%t TableListField_PageControls_ss.OF 'of' is 'Example: View 1 of 2' %>
+            $NumRecords
+        </span>
+    </td>
+</tr>

tests/GridFieldConfigurablePaginatorTest.php

@@ -0,0 +1,238 @@
+<?php
+
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Forms\GridField\GridField;
+use SilverStripe\Forms\GridField\GridField_FormAction;
+use SilverStripe\ORM\ArrayList;
+use Symbiote\GridFieldExtensions\GridFieldConfigurablePaginator;
+
+class GridFieldConfigurablePaginatorTest extends SapphireTest
+{
+    /**
+     * @var GridField
+     */
+    protected $gridField;
+
+    public function setUp()
+    {
+        parent::setUp();
+
+        // Some dummy GridField list data
+        $data = ArrayList::create();
+        for ($i = 1; $i <= 130; $i++) {
+            $data->push(array('ID' => $i));
+        }
+
+        $this->gridField = GridField::create('Mock', null, $data);
+    }
+
+    public function testGetTotalRecords()
+    {
+        $paginator = new GridFieldConfigurablePaginator;
+        $paginator->setGridField($this->gridField);
+
+        $this->assertSame(130, $paginator->getTotalRecords());
+    }
+
+    public function testGetFirstShown()
+    {
+        $paginator = new GridFieldConfigurablePaginator;
+        $paginator->setGridField($this->gridField);
+
+        // No state
+        $this->assertSame(1, $paginator->getFirstShown());
+
+        // With a state
+        $paginator->setFirstShown(123);
+        $this->assertSame(123, $paginator->getFirstShown());
+
+        // Too high!
+        $paginator->setFirstShown(234);
+        $this->assertSame(1, $paginator->getFirstShown());
+    }
+
+    public function testGetLastShown()
+    {
+        $paginator = new GridFieldConfigurablePaginator(20, array(10, 20, 30));
+        $paginator->setGridField($this->gridField);
+
+        $this->assertSame(20, $paginator->getLastShown());
+
+        $paginator->setFirstShown(5);
+        $this->assertSame(24, $paginator->getLastShown());
+    }
+
+    public function testGetTotalPages()
+    {
+        $paginator = new GridFieldConfigurablePaginator(20, array(20, 40, 60));
+        $paginator->setGridField($this->gridField);
+
+        // Default calculation
+        $this->assertSame(7, $paginator->getTotalPages());
+
+        // With a standard "first shown" record number, e.g. page 2
+        $paginator->setFirstShown(21);
+        $this->assertSame(7, $paginator->getTotalPages());
+
+        // Non-standard "first shown", e.g. when a page size is changed at page 3. In this case the first page is
+        // 20 records, the second page is 7 records, third page 20 records, etc
+        $paginator->setFirstShown(27);
+        $this->assertSame(8, $paginator->getTotalPages());
+
+        // ... and when the page size has also been changed. In this case the first page is 57 records, second page
+        // 60 records and last page is 13 records
+        $paginator->setFirstShown(57);
+        $paginator->setItemsPerPage(60);
+        $this->assertSame(3, $paginator->getTotalPages());
+    }
+
+    public function testItemsPerPageIsSetToFirstInPageSizesListWhenChanged()
+    {
+        $paginator = new GridFieldConfigurablePaginator(20, array(20, 40, 60));
+        $paginator->setGridField($this->gridField);
+
+        // Initial state, should be what was provided to the constructor
+        $this->assertSame(20, $paginator->getItemsPerPage());
+
+        $paginator->setPageSizes(array(50, 100, 200));
+
+        // Set via public API, should now be set to 50
+        $this->assertSame(50, $paginator->getItemsPerPage());
+    }
+
+    public function testGetCurrentPreviousAndNextPages()
+    {
+        $paginator = new GridFieldConfigurablePaginator(20, array(20, 40, 60));
+        $paginator->setGridField($this->gridField);
+
+        // No page selected (first page)
+        $this->assertSame(1, $paginator->getCurrentPage());
+        $this->assertSame(1, $paginator->getPreviousPage());
+        $this->assertSame(2, $paginator->getNextPage());
+
+        // Second page
+        $paginator->setFirstShown(21);
+        $this->assertSame(2, $paginator->getCurrentPage());
+        $this->assertSame(1, $paginator->getPreviousPage());
+        $this->assertSame(3, $paginator->getNextPage());
+
+        // Third page
+        $paginator->setFirstShown(41);
+        $this->assertSame(3, $paginator->getCurrentPage());
+        $this->assertSame(2, $paginator->getPreviousPage());
+        $this->assertSame(4, $paginator->getNextPage());
+
+        // Fourth page, partial record count
+        $paginator->setFirstShown(42);
+        $this->assertSame(4, $paginator->getCurrentPage());
+        $this->assertSame(3, $paginator->getPreviousPage());
+        $this->assertSame(5, $paginator->getNextPage());
+
+        // Last page (default paging)
+        $paginator->setFirstShown(121);
+        $this->assertSame(7, $paginator->getCurrentPage());
+        $this->assertSame(6, $paginator->getPreviousPage());
+        $this->assertSame(7, $paginator->getNextPage());
+
+        // Non-standard page size should recalculate the page numbers to be relative to the page size
+        $paginator->setFirstShown(121);
+        $paginator->setItemsPerPage(60);
+        $this->assertSame(3, $paginator->getCurrentPage());
+        $this->assertSame(2, $paginator->getPreviousPage());
+        $this->assertSame(3, $paginator->getNextPage());
+    }
+
+    public function testPageSizesAreConfigurable()
+    {
+        // Via constructor
+        $paginator = new GridFieldConfigurablePaginator(3, array(2, 4, 6));
+        $this->assertSame(3, $paginator->getItemsPerPage());
+        $this->assertSame(array(2, 4, 6), $paginator->getPageSizes());
+
+        // Via public API
+        $paginator->setPageSizes(array(10, 20, 30));
+        $this->assertSame(array(10, 20, 30), $paginator->getPageSizes());
+
+        // Via default configuration
+        $paginator = new GridFieldConfigurablePaginator;
+        $default = Config::inst()->get(GridFieldConfigurablePaginator::class, 'default_page_sizes');
+        $this->assertSame($default, $paginator->getPageSizes());
+    }
+
+    public function testGetPageSizesAsList()
+    {
+        $paginator = new GridFieldConfigurablePaginator(10, array(10, 20, 30));
+        $this->assertDOSEquals(array(
+            array('Size' => '10', 'Selected' => true),
+            array('Size' => '20', 'Selected' => false),
+            array('Size' => '30', 'Selected' => false),
+        ), $paginator->getPageSizesAsList());
+    }
+
+    /**
+     * @expectedException Exception
+     * @expectedExceptionMessage No GridField available yet for this request!
+     */
+    public function testGetGridFieldThrowsExceptionWhenNotSet()
+    {
+        $paginator = new GridFieldConfigurablePaginator;
+        $paginator->getGridField();
+    }
+
+    public function testGetPagerActions()
+    {
+        $controls = array(
+            'prev' => array(
+                'title' => 'Previous',
+                'args' => array(
+                    'next-page' => 123,
+                    'first-shown' => 234
+                ),
+                'extra-class' => 'ss-gridfield-previouspage',
+                'disable-previous' => false
+            ),
+            'next' => array(
+                'title' => 'Next',
+                'args' => array(
+                    'next-page' => 234,
+                    'first-shown' => 123
+                ),
+                'extra-class' => 'ss-gridfield-nextpage',
+                'disable-next' => true
+            )
+        );
+
+        $gridField = $this->getMockBuilder(GridField::class)->disableOriginalConstructor()->getMock();
+        $paginator = new GridFieldConfigurablePaginator;
+        $result = $paginator->getPagerActions($controls, $gridField);
+
+        $this->assertCount(2, $result);
+        $this->assertArrayHasKey('next', $result);
+        $this->assertContainsOnlyInstancesOf(GridField_FormAction::class, $result);
+
+        $this->assertFalse($result['prev']->isDisabled());
+
+        $this->assertTrue((bool) $result['next']->hasClass('ss-gridfield-nextpage'));
+        $this->assertTrue($result['next']->isDisabled());
+    }
+
+    public function testSinglePageWithLotsOfItems()
+    {
+        $paginator = new GridFieldConfigurablePaginator(null, array(100, 200, 300));
+        $this->assertSame(100, $paginator->getItemsPerPage());
+    }
+
+    /**
+     * Set something to the GridField's paginator state data
+     *
+     * @param  string $key
+     * @param  mixed  $value
+     * @return $this
+     */
+    protected function setState($key, $value)
+    {
+        $this->gridField->State->GridFieldConfigurablePaginator->$key = $value;
+        return $this;
+    }
+}